A322374 Where records occur in A322373.

1, 6, 12, 30, 60, 120, 180, 360, 420, 720, 840, 1260, 2520, 5040, 7920, 9240, 13860, 18480, 25200, 27720, 50400, 55440, 83160, 110880, 138600, 163800, 166320, 240240, 277200, 327600, 332640, 360360, 554400, 720720, 1081080, 1413720, 1441440, 1801800, 2162160, 2827440

Offset

1,2

Links

Table of n, a(n) for n=1..40.

Example

The divisors of 6 are {1, 2, 3, 6} and gcd(3, 6) = 3 > 1 but gcd(2, 3, 6) = 1. As 2 is the second divisor of 6, A322373(6) = 2. This is a new record; A322373(k) < 2 for all k < 6. Therefore, 6 is in the sequence.

Mathematica

With[{s = Array[LengthWhile[#, # == 1 &] &@ Reverse@ FoldList[GCD[#1, #2] &, Reverse@ Divisors@ #] &, 10^6]}, Map[First@ FirstPosition[s, #] &, Union@ FoldList[Max, s]]] (* Michael De Vlieger, Dec 31 2018 *)

Prog

(PARI) upto(n) = my(r=0, res=List()); for(i=1, n, c=A322373(i); if(c > r, listput(res, i); print1(i", "); r = c)); res \\ David A. Corneth, Dec 09 2018

Crossrefs

Cf. A322373.

Sequence in context: A229746 A256579 A357197 * A351694 A014131 A236539

Adjacent sequences: A322371 A322372 A322373 * A322375 A322376 A322377

Keyword

nonn

Author

David A. Corneth, Dec 09 2018

Status

approved